Certain structural materials, such as concrete, are very strong in compression, but relatively weak in tension and/or shear, and can behave in a brittle manner when cracks form. Various reinforcement structures can be used to address these issues, such as metal bars, wires, and similar structures. For example, reinforcing structures made of steel or other metals are typically embedded within the concrete to absorb tensile and/or shear loads and to resist brittle fracture and crack propagation. This can increase strength and durability and decrease the potential failure rate of the material.
Concrete pipe structures can benefit from such embedded reinforcement structures. For example, circular concrete pipe may experience shear and tensile forces when a radial force is exerted on the pipe, which can occur frequently in use. Square or rectangular concrete pipe (also known as box culvert) can experience similar tensile and shear loads when a force is exerted on one of the side walls of the pipe, as well as shear loads at the corners of the pipe. Thus, significant reinforcement structures are often provided at the points where these stresses are most frequently concentrated in the use of the concrete pipe. Such reinforcement structures can be provided in the form of a mat or other interconnected structure, which provides increased reinforcement over a large area. However, existing reinforcement structures for concrete pipe have certain disadvantages. For example, one type of existing reinforcement structure utilizes stirrups or prongs that are welded in place. In this configuration, the weld forms a weak point, such that the tensile strength of the structure is often limited by the strength of the weld (which can be significantly lower than the wire's tensile strength in some cases). Another type of existing reinforcement structure utilizes long oscillating reinforcement elements that are arranged roughly parallel to each other. Reinforcement structures of this type can provide increased tensile strength, however, these structures provide limited options for spacing, alignment, and orientation of the reinforcement elements relative to each other. This, in turn, can limit the number of applications in which these reinforcement structures can be used.
Thus, while certain reinforcement structures according to existing designs provide a number of advantageous features, they nevertheless have certain limitations. The present disclosure seeks to overcome certain of these limitations and other drawbacks of the prior art, and to provide new features not heretofore available.